Immobilized beta-cyclodextrin-based silica vs polymer monoliths for chiral nano liquid chromatographic separation of racemates

摘要

The enantioselectivity of immobilized beta-cyclodextrin phenyl carbamate-based silica monolithic capillary columns was compared to our previously described polymer counterpart. 2,3.6-Tris(phenylcarbamoyI)beta-cyclodextrin-6-methacrylate was used as a functional monomer for the preparation of beta-cyclodextrin (beta-CD)-based silica and polymer monoliths. The silica monoliths were prepared via the sot gel technique in fused silica capillary followed by modification of the bare silica monoliths with an anchor group prior to polymerization with beta-CD methacrylate using either 2,2'-azobis(isobutyronitrile) or benzoylperoxide as radical initiators. On the other hand, the polymer monoliths were prepared via the copolymerization of beta-CD methacrylate and ethylene glycol dimethacrylate in different ratios in situ in fused silica capillary. The prepared silica/polymer monoliths were investigated for the chiral separation of different classes of pharmaceuticals namely; alpha- and beta-blockers, anti-inflammatory drugs, antifungal drugs, dopamine antagonists, norepinephrine-dopamine reuptake inhibitors, catecholamines, sedative hypnotics, diuretics, antihistaminics, anticancer drugs and antiarrhythmic drugs. Baseline separation was achieved for alprenolol, bufuralol, carbuterol, cizolertine. desmethylcizolertine, eticlopride, ifosfamide, 1-indanol, propranolol, tebuconazole, tertatolol and o-methoxymandelic acid under reversed phase conditions using mobile phase composed of methanol and water. The silica-based monoliths showed a comparative enantioselectivity to the polymer monoliths. Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.